U.S. Pat. No. 3,620,816, which issued to the same individuals named as applicants herein, describes a process of diffusion alloying the surface of a ferrous part in a molten lead medium. In that process, elements such as chromium are dissolved into the molten lead, and the lead is placed in contact with the ferrous part to be surfaced. The diffusing element is alloyed into the surface of the part by metallic diffusion at elevated temperatures. The process has been applied simultaneously to multiple small parts where bonding of the parts must be avoided. U.S. Pat. No. 3,778,299, which also issued to the same individuals names as applicants herein, describes a method to avoid bonding in the processing of multiple small parts. In these instances the parts need not be in contact during processing.
However, there are situations where the part which is to be surface alloyed must be in contact with some other member while the processing takes place. For example, the part may be held together by a fixture during processing in which case it is necessary that the fixture not be bonded to the part. Also, surface alloying ferrous-based sheet may be accomplished in a bath of relatively small size by coiling it first. After the processing has been completed, the sheet can be uncoiled. It is important to prevent points on adjacent flights of the coil from becoming bonded to each other.